BERLIN (AP) — Lothar Bisky, who after German reunification helped steer discredited East German communists into the mainstream of national politics, died Tuesday at age 71.

Bisky’s death was announced by the Left Party, which he helped establish and was co-chairman of for three years. No cause of death was announced, but Bisky cited unspecified health reasons when he stepped down last year from a European Parliament post.

Bisky was among a handful of East German Communists who took the helm of the discredited former ruling Socialist Unity Party following the opening of the Berlin Wall and the ouster of the hard-line leadership. They transformed the former Stalinist party into a Western-style left-wing movement that still enjoys support, mostly in former Communist areas of eastern Germany.

Bisky was born in Pommerania, now Poland, on Aug. 17, 1941. His family fled the advancing Soviet army in 1945, and settled in West Germany. When he was 18, however, Bisky moved to East Germany because he thought prospects for his future were better in a free-education Marxist state.

He joined the ruling Communist party in 1963, serving later as rector of the College for Film and Television in the Berlin suburb of Babelsberg. But he did not rise to senior positions in the party — possibly because of his years living in West Germany — until Communist hardliners were purged after the Berlin Wall was opened in 1989.

Following German reunification, he served as chairman of the Party of Democratic Socialism, the reorganized successor of East Germany’s former ruling party, from 1993 until 2000 and again from 2003 until 2007.

Bisky was elected to Germany’s Parliament in 2005, but lost election as one of the six parliamentary vice presidents because of reports that he had been an informant for the East German secret police.

Two years later he steered the PDS into a merger with other left-wing groups to form the Left Party, which he helped lead from 2007 to 2010.

In his final years, Bisky focused on the European Parliament, where he served as chairman of the left-wing bloc until he stepped down last year. He also served for more than two years as publisher of Neues Deutschland, the former official Communist newspaper which was privatized after East Germany collapsed.

He leaves a wife and two sons, prominent painter Norbert Bisky and writer Jens Bisky. A third son, Stephan Bisky, died in 2008.